/*
   -----------------------------------------------------------------------------
   This source file is part of OGRE
   (Object-oriented Graphics Rendering Engine)
   For the latest info, see http://www.ogre3d.org/

   Copyright (c) 2000-2011 Torus Knot Software Ltd

   Permission is hereby granted, free of charge, to any person obtaining a copy
   of this software and associated documentation files (the "Software"), to deal
   in the Software without restriction, including without limitation the rights
   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   copies of the Software, and to permit persons to whom the Software is
   furnished to do so, subject to the following conditions:

   The above copyright notice and this permission notice shall be included in
   all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   THE SOFTWARE.
   -----------------------------------------------------------------------------
   */
#include "ColorValue.h"
#include "Math.h"

const ColorValue ColorValue::ZERO = ColorValue(0.0,0.0,0.0,0.0);
const ColorValue ColorValue::Black = ColorValue(0.0,0.0,0.0);
const ColorValue ColorValue::White = ColorValue(1.0,1.0,1.0);
const ColorValue ColorValue::Red = ColorValue(1.0,0.0,0.0);
const ColorValue ColorValue::Green = ColorValue(0.0,1.0,0.0);
const ColorValue ColorValue::Blue = ColorValue(0.0,0.0,1.0);

//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
ABGR ColorValue::getAsABGR(void) const
#else
RGBA ColorValue::getAsRGBA(void) const
#endif
{
	uint8 val8;
	uint32 val32 = 0;

	// Convert to 32bit pattern
	// (RGBA = 8888)

	// Red
	val8 = static_cast<uint8>(r * 255);
	val32 = val8 << 24;

	// Green
	val8 = static_cast<uint8>(g * 255);
	val32 += val8 << 16;

	// Blue
	val8 = static_cast<uint8>(b * 255);
	val32 += val8 << 8;

	// Alpha
	val8 = static_cast<uint8>(a * 255);
	val32 += val8;

	return val32;
}
//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
BGRA ColorValue::getAsBGRA(void) const
#else
ARGB ColorValue::getAsARGB(void) const
#endif
{
	uint8 val8;
	uint32 val32 = 0;

	// Convert to 32bit pattern
	// (ARGB = 8888)

	// Alpha
	val8 = static_cast<uint8>(a * 255);
	val32 = val8 << 24;

	// Red
	val8 = static_cast<uint8>(r * 255);
	val32 += val8 << 16;

	// Green
	val8 = static_cast<uint8>(g * 255);
	val32 += val8 << 8;

	// Blue
	val8 = static_cast<uint8>(b * 255);
	val32 += val8;


	return val32;
}
//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
ARGB ColorValue::getAsARGB(void) const
#else
BGRA ColorValue::getAsBGRA(void) const
#endif
{
	uint8 val8;
	uint32 val32 = 0;

	// Convert to 32bit pattern
	// (ARGB = 8888)

	// Blue
	val8 = static_cast<uint8>(b * 255);
	val32 = val8 << 24;

	// Green
	val8 = static_cast<uint8>(g * 255);
	val32 += val8 << 16;

	// Red
	val8 = static_cast<uint8>(r * 255);
	val32 += val8 << 8;

	// Alpha
	val8 = static_cast<uint8>(a * 255);
	val32 += val8;


	return val32;
}
//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
RGBA ColorValue::getAsRGBA(void) const
#else
ABGR ColorValue::getAsABGR(void) const
#endif
{
	uint8 val8;
	uint32 val32 = 0;

	// Convert to 32bit pattern
	// (ABRG = 8888)

	// Alpha
	val8 = static_cast<uint8>(a * 255);
	val32 = val8 << 24;

	// Blue
	val8 = static_cast<uint8>(b * 255);
	val32 += val8 << 16;

	// Green
	val8 = static_cast<uint8>(g * 255);
	val32 += val8 << 8;

	// Red
	val8 = static_cast<uint8>(r * 255);
	val32 += val8;


	return val32;
}
//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
void ColorValue::setAsABGR(const ABGR val)
#else
void ColorValue::setAsRGBA(const RGBA val)
#endif
{
	uint32 val32 = val;

	// Convert from 32bit pattern
	// (RGBA = 8888)

	// Red
	r = ((val32 >> 24) & 0xFF) / 255.0f;

	// Green
	g = ((val32 >> 16) & 0xFF) / 255.0f;

	// Blue
	b = ((val32 >> 8) & 0xFF) / 255.0f;

	// Alpha
	a = (val32 & 0xFF) / 255.0f;
}
//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
void ColorValue::setAsBGRA(const BGRA val)
#else
void ColorValue::setAsARGB(const ARGB val)
#endif
{
	uint32 val32 = val;

	// Convert from 32bit pattern
	// (ARGB = 8888)

	// Alpha
	a = ((val32 >> 24) & 0xFF) / 255.0f;

	// Red
	r = ((val32 >> 16) & 0xFF) / 255.0f;

	// Green
	g = ((val32 >> 8) & 0xFF) / 255.0f;

	// Blue
	b = (val32 & 0xFF) / 255.0f;
}
//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
void ColorValue::setAsARGB(const ARGB val)
#else
void ColorValue::setAsBGRA(const BGRA val)
#endif
{
	uint32 val32 = val;

	// Convert from 32bit pattern
	// (ARGB = 8888)

	// Blue
	b = ((val32 >> 24) & 0xFF) / 255.0f;

	// Green
	g = ((val32 >> 16) & 0xFF) / 255.0f;

	// Red
	r = ((val32 >> 8) & 0xFF) / 255.0f;

	// Alpha
	a = (val32 & 0xFF) / 255.0f;
}
//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
void ColorValue::setAsRGBA(const RGBA val)
#else
void ColorValue::setAsABGR(const ABGR val)
#endif
{
	uint32 val32 = val;

	// Convert from 32bit pattern
	// (ABGR = 8888)

	// Alpha
	a = ((val32 >> 24) & 0xFF) / 255.0f;

	// Blue
	b = ((val32 >> 16) & 0xFF) / 255.0f;

	// Green
	g = ((val32 >> 8) & 0xFF) / 255.0f;

	// Red
	r = (val32 & 0xFF) / 255.0f;
}
//---------------------------------------------------------------------
bool ColorValue::operator==(const ColorValue& rhs) const
{
	return (r == rhs.r &&
			g == rhs.g &&
			b == rhs.b &&
			a == rhs.a);
}
//---------------------------------------------------------------------
bool ColorValue::operator!=(const ColorValue& rhs) const
{
	return !(*this == rhs);
}
//---------------------------------------------------------------------
void ColorValue::setHSB(float hue, float saturation, float brightness)
{
	// wrap hue
	if (hue > 1.0f)
	{
		hue -= (int)hue;
	}
	else if (hue < 0.0f)
	{
		hue += (int)hue + 1;
	}
	// clamp saturation / brightness
	saturation = std::min(saturation, (float)1.0);
	saturation = std::max(saturation, (float)0.0);
	brightness = std::min(brightness, (float)1.0);
	brightness = std::max(brightness, (float)0.0);

	if (brightness == 0.0f)
	{   
		// early exit, this has to be black
		r = g = b = 0.0f;
		return;
	}

	if (saturation == 0.0f)
	{   
		// early exit, this has to be grey

		r = g = b = brightness;
		return;
	}


	float hueDomain  = hue * 6.0f;
	if (hueDomain >= 6.0f)
	{
		// wrap around, and allow mathematical errors
		hueDomain = 0.0f;
	}
	unsigned short domain = (unsigned short)hueDomain;
	float f1 = brightness * (1 - saturation);
	float f2 = brightness * (1 - saturation * (hueDomain - domain));
	float f3 = brightness * (1 - saturation * (1 - (hueDomain - domain)));

	switch (domain)
	{
		case 0:
			// red domain; green ascends
			r = brightness;
			g = f3;
			b = f1;
			break;
		case 1:
			// yellow domain; red descends
			r = f2;
			g = brightness;
			b = f1;
			break;
		case 2:
			// green domain; blue ascends
			r = f1;
			g = brightness;
			b = f3;
			break;
		case 3:
			// cyan domain; green descends
			r = f1;
			g = f2;
			b = brightness;
			break;
		case 4:
			// blue domain; red ascends
			r = f3;
			g = f1;
			b = brightness;
			break;
		case 5:
			// magenta domain; blue descends
			r = brightness;
			g = f1;
			b = f2;
			break;
	}


}
//---------------------------------------------------------------------
void ColorValue::getHSB(float* hue, float* saturation, float* brightness) const
{

	float vMin = std::min(r, std::min(g, b));
	float vMax = std::max(r, std::max(g, b));
	float delta = vMax - vMin;

	*brightness = vMax;

	if (Math::floatEqual(delta, 0.0f, 1e-6))
	{
		// grey
		*hue = 0;
		*saturation = 0;
	}
	else                                    
	{
		// a color
		*saturation = delta / vMax;

		float deltaR = (((vMax - r) / 6.0f) + (delta / 2.0f)) / delta;
		float deltaG = (((vMax - g) / 6.0f) + (delta / 2.0f)) / delta;
		float deltaB = (((vMax - b) / 6.0f) + (delta / 2.0f)) / delta;

		if (Math::floatEqual(r, vMax))
			*hue = deltaB - deltaG;
		else if (Math::floatEqual(g, vMax))
			*hue = 0.3333333f + deltaR - deltaB;
		else if (Math::floatEqual(b, vMax)) 
			*hue = 0.6666667f + deltaG - deltaR;

		if (*hue < 0.0f) 
			*hue += 1.0f;
		if (*hue > 1.0f)
			*hue -= 1.0f;
	}


}


